NONLINEAR FRACTURE-MECHANICS FOR AN ELASTIC BELL MATERIAL

A method of analysis is proposed to perform realistic asymptotic inves tigations in nonlinear fracture mechanics. It is based on the use, con ceptually new in this context, of constrained elasticity. More specifi cally, within the framework of finite elasticity, a crack analysis is formulated for a material subjected to the Bell constraint. (Such a ma terial constraint, suggested by experimental tests requires that the s um of the principal stretches must be 3.) General far-field loading (m ixed-mode loading) and conditions ensuring vanishing tractions at the crack faces are considered. By means of an asymptotic procedure, the d eformation and stress fields near the crack tip are computed, showing how these cease to be singular. Further unexpected results are discuss ed.